Fair Value Measurements (Details) - Debt Obligations - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt obligations, net	$ 2,320,719,000	$ 2,354,099,000
Deferred financing costs	15,395,000	17,204,000
Debt Instrument, Unamortized Discount (Premium), Net	(1,352,000)	(1,218,000)
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	2,314,818,000	2,393,433,000
Term Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt obligations, net	1,608,378,000	1,636,470,000
Term Loans | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	1,595,050,000	1,656,765,000
Secured Portfolio Loan Facilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt obligations, net	390,890,000	390,780,000
Secured Portfolio Loan Facilities | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	391,157,000	399,054,000
Mortgages
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt obligations, net	321,451,000	326,849,000
Mortgages | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	$ 328,611,000	$ 337,614,000